White lesions

Question 1

Explain why the normal mucosa appears pink

Answer 1

• Light shines through the epithelium into the underlying connective tissues
• Light reflects from the haemoglobin in erythrocytes found in the vasculature of the connective tissues
• That light is bounced back to the eye of the observer and we see “pink”.

Question 2

Explain why white lesions appear white

Answer 2

A blockage of light which is normally reflected from the haemoglobin in erythrocytes in the blood vessels of the connective tissue to the observer’s eyes

Question 3

List 6 examples of white lesions

Answer 3

• Hyperkeratosis
• Parakeratosis
• Acanthosis
• Spongiosis (Intracellular Oedema)
• Ulceration and Inflammation
• Superficial Fungal Infection

Question 4

Explain what hyperkeratosis is

Answer 4

• Hyper(ortho)keratosis is the excess formation of mature keratin
• It is likely the most common reason for a lesion to appear white
• The thick layer of material covering the epithelium is orthokeratin.

Question 5

Explain what parakeratosis is

Answer 5

• Parakeratosis is immature keratin formation. Immature keratin has nuclei in it, unlike orthokeratin
• Often, orthokeratin and parakeratin are present together in the same lesion

Question 6

Define acanthosis

Answer 6

• Acanthosis is thickening of the epithelium due to increased number of cells. (Hyperplasia)
• This has the effect of placing an avascular band of tissue between the observer and the underlying blood vessels.

Question 7

Define spongiosis

Answer 7

• Spongiosis (or intracellular oedema)

* The epithelium may collect fluid or become oedematous.

Question 8

Explain why inflammation can appear as white

Answer 8

• Chronic inflammation in the connective tissue has a tendency to block the red reflection
• This has the effect of thickening the area between the surface and the underlying blood vessels.

Question 9

Explain why ulceration appears as white

Answer 9

Ulcerated areas may have a yellowish white appearance due to the deposition of a thick layer of coagulated exudate on the surface.

Question 10

Explain superficial fungal debris

Answer 10

• White lesion on the oral mucosal surface reflecting fungal colonies (e.g. candida) infecting the surface epithelium
• Often presents with inflammation and epithelial hyperplasia (acanthosis).

Question 11

Explain what to do when you see a patient with a lesion

Answer 11

• I/O and E/O
• Medical history, social history
• Onset, severity, frequency, pain, signs/ symptoms
• Location, distribution, size, shape/margins, colour, consistency, tactility (e.g. Induration, Fixation), pain on palpation, interaction with neighbouring structures

Question 12

List the possible categories that a lesion could fall

Answer 12

• Developmental/Hereditary
• Traumatic (Physical, Chemical, Thermal, Radiation)
• Infective (Bacterial, Viral, Fungal)
• Immune Mediated
• Metabolic
• Nutritional
• Neoplastic
• Iatrogenic (Procedural/Treatment)
• Idiopathic (No Known Cause)

Question 13

Explain what Fordyce granules are

Answer 13

• Fordyce’s Granules are benign sebaceous glands. They are a variation of normal oral phenotype
• Asymptomatic, yellow-white 1-3mm macule and papules typically seen on buccal mucosa and upper lip vermillion
• Generally bilateral and symmetrically distributed.

Question 14

Explain what white sponge nevus is in terms of genetics and appearance

Answer 14

• Rare autosomal dominant disorder which affects the oral and other mucosae; but not the skin
• Asymptomatic, thick, white spongy plaques usually on buccal mucosa, ventral tongue, lip mucosa and soft palate
• Mutation in genes associated with keratin-4 (KRT4) or keratin-13 (KRT13); resulting in keratin instability and aggregation of tonofilaments
• This is a benign inherited condition –there is no treatment.

Question 15

Explain what leukodema is

Answer 15

• Leukoedemais a variation of normal.
• Caused by mild local irritation – e.g. smoking, toothpastes, mouthrinses, physical trauma
• Asymptomatic, white-grey translucent linear reticulations, commonly on buccal mucosa, and less frequently on lip mucosa or ventral tongue
• There is complete disappearance of these reticulations upon stretching the mucosa (the “stretch test”) is a diagnostic feature.

Question 16

Explain what morsicatio mucosae oris

Answer 16

• A benign, chronic trauma-induced lesion of the oral mucosa
• Asymptomatic, poorly demarcated, thickened, white, ragged, papules and plaques
• The most common sites are the buccal mucosae (Morsicatio Buccarum), lateral/ventral tongue (Morsicatio Linguarum) and lower lip mucosa (Morsicatio Labiorum)
• Para-functional Habit?

Question 17

Explain what nicotinic stomatitis is and how it occurs

Answer 17

• An inflammatory condition of the hard palate mucosa; commonly seen with pipe, cigar or reverse smokers
• As a result of chronic exposure to heat, the palatal mucosa becomes hyperkeratotic and thickened, and the surface often contains scattered 1-3mm red punctuate papules which are the inflamed orifices of minor salivary gland ducts

Question 18

Explain what hairy tongue is

Answer 18

• Hairy Tongueis a benign elongation of filiform papillae and retention of keratin resulting in hair-like appearance on the dorsum of the tongue
• Can be stained by food, tobacco or chromogenic bacteria
• Dry Mouth – lack of saliva to clear keratin
• Poor Diet – reduced mechanical desquamation of keratin if consuming soft, processed foods.

Question 19

Explain benign migratory glossitis

Answer 19

• A chronic benign inflammatory condition involving relapsing-recurring loss of filiform papillae. Can be sensitive to spicy or acidic food.
• Unknown aetiology. Often occurs in patients with a history of eczema, allergies, or psoriasis
• Lesions tend to flare when patients are under stress or ill
• Self-limiting, heals within a few days; but does recur.

Question 20

Explain what candidiasis is

Answer 20

• Occurs as an opportunistic infection. Can be a strong predictor of AIDS progression
• Pseudomembranous candidiasis: white, curdy papules and plaques composed of tangled hyphae, yeast, and desquamated epithelial cells
• Hyperplastic candidiasis: asymptomatic white plaques that cannot be scraped off.

Question 21

Explain oral hairy leukoplakia

Answer 21

• A benign condition of the tongue caused by Epstein-Barr virus (EBV)
• It is most frequently seen in immunocompromised patients such as those with HIV/AIDS as well as in patients on immunosuppressive therapy such as organ transplant recipients.
• Presents most frequently on the lateral borders of the tongue as an asymptomatic, white, adherent plaque with linear folds that run parallel to the long axis of the tongue.

Question 22

Explain what oral lichen planus is as well as its sub classifications

Answer 22

• Immune-mediated condition in which basal cells are destroyed by cytotoxic CD8+ T cells
• Typical oral LP is almost always bilateral and symmetric and affects the buccal mucosa, tongue, and attached gingiva.

Lesions may be classified into the following, often overlapping categories:
• Reticular - white intersecting loops and lines forming Wickham striae or papules
• Erosive– i.e. desquamative gingivitis
• Ulcerative– yellow fibrin membrane with an erythematous rim and subtle reticulations
• Atrophic– loss of papillae and diffuse keratosis or white papules
• Bullous– presenting with bullae which break down to form erosive OLP

Question 23

Explain what lichenoid reactions are, how it is caused and how it appears histologically

Answer 23

• These lesions are collectively termed Lichenoid Reactions and encompass lichenoid drug reactions and lichenoid reactions to dental materials
• Anti-hypertensives, diuretics, NSAIDs, anti-convulsants, anti-malarials, chemotherapy agents, amalgam, gold can cause them
• May range from asymptomatic striae and plaque-like lesions to painful erythematous and ulcerative lesions.
• Histopathologically OLR appear similar to OLP -showing a band-like infiltrate (mainly T cell) within the lamina propria as well as degeneration of the basal cell layer.

Question 24

Explain what actinic cheilitis is

Answer 24

• Actinic Chelitisis most commonly due to chronic sun exposure and is typically seen on the lower lip of adults with fair skin who have significant sun exposure and may be as common as 9–40%
• UV (ultraviolet) radiation-induced DNA damage leads to morphological changes of keratinocytes
• The affected lip is often dry, scaly, fragile, cracked, with thickened plaques and papules
• There may also be white or yellow areas, with crusting, erosions, or focal ulceration

Question 25

Define leukoplakia

Answer 25

• Leukoplakia is defined as a “white plaque of questionable risk having excluded (other) known diseases or disorders that carry no increased risk for cancer”
• Approximately 40% of leukoplakia show features of dysplasia, carcinoma-in-situ or invasive squamous cell carcinoma
• The other 60% will show hyperkeratosis or parakeratosis, acanthosis, or atrophy, with or without inflammation; these have been given the name keratosis of unknown significance
• The greater the degree of dysplasia; the greater the risk of malignant transformation.

Question 26

List some important clinical steps to take when you see a lesion in a patient

Answer 26

• All lesions should be palpated to evaluate for firmness or induration(and fixation), which may indicate the presence of an invasive carcinoma
• The sites with the highest incidence of development of squamous cell carcinoma are the ventral tongue, floor of mouth, buccal mucosa, and gingiva
• Although the soft palate is an uncommon site for leukoplakia, it has a high prevalence of dysplasia or carcinoma when it does occur.